Hydroxycitric acid compositions, pharmaceutical and dietary supplements and food products made therefrom, and methods for their use in reducing body weight

ABSTRACT

Hydroxycitric acid compositions which comprise approximately 14 to 26% by weight of calcium, and approximately 24 to 40% by weight of potassium or approximately 14 to 24% by weight of sodium, or a mixture thereof, each calculated as a percentage of the total hydroxycitric acid content of the composition, together with dietary supplements and food products containing such compositions and methods for utilizing such compositions, dietary supplements and food products to reduce body weight in mammals are disclosed.

PRIORITY CLAIM

This application is a continuation of U.S. patent application Ser. No.09/463,024, titled: Hydroxycitric Acid Compositions, Pharmaceutical andDietary Supplements and Food Products Made There from, and Methods ForTheir Use In Reducing Body Weight, inventor: G. Ganga Raju, filed Feb.15, 2002 which claims priority to PCT application PCT/US98/14481 titled:Hydroxycitric Acid Compositions, Pharmaceutical and Dietary Supplementsand Food Products Made Therefrom, and Methods For Their Use In ReducingBody Weight, inventor: G. Ganga Raju, filed Jul. 13, 1998, which claimspriority to U.S. patent application Ser. No. 08/892,414, titled:Hydroxycitric Acid Compositions, Pharmaceutical and Dietary Supplementsand Food Products Made There from, and Methods For Their Use In ReducingBody Weight, inventor: G. Ganga Raju, filed Jul. 14, 1997. Theseapplications are herein incorporated by reference in their entirety.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is related to the following application, which wasfiled of even date herewith:

“Hydroxycitric Acid Compositions, Pharmaceutical and Dietary Supplementsand Food Products Made Therefrom, and Methods For Their Use In ReducingBody Weight,” by G. Ganga Raju, Attorney Docket No. IHEAL-01063US2SRM/AGC.

BACKGROUND OF THE INVENTION

Hydroxycitric Acid has been known for many years to be beneficial forthe control and reduction of mammalian body weight. In particular, aspecific stereoisomer of hydroxycitric acid, the (−)hydroxycitric acidisomer and derivatives thereof, is known to inhibit fatty acid andcholesterol synthesis and to function as a natural anorectic agent inmammals.

The stereoisomers of hydroxycitric acid are related structurally tocitric acid wherein a hydroxy group is substituted for one of the fourmethylene hydrogens. Thus, there are four possible stereoisomers ofhydroxycitric acid. Of these four stereoisomers, the (−) hydroxycitricacid isomer has been found to substantially inhibit fatty acid synthesisin biological systems in profused organs and intact mammals, andparticularly in non-ruminant mammals.

It has also been known that the particular stereoisomer of interest, inboth free acid and lactone forms, is found in the rind of the fruits ofGarcinia species, for example, Garcinia cambogia, Garcinia atroviridisand Garcinia indica, which are native to the Indian subcontinent. Thehydroxycitric acid component can be obtained by isolation from the fruitof Garcinia species using known procedures, for example Lewis, Y. S.“Methods in Enzymology” (J. M. Lowenstein, Ed., Vol. 13, pg. 613)(Academic Press, N.Y. 1969), and U.S. Pat. No. 5,536,516.

As an inhibitor of the synthesis of fatty acids and cholesterol,hydroxycitric acid has been shown to significantly reduce the bodyweight and lower lipid accumulation in rats. See, e.g. Sergio, W.Medical Hypothesis 27:39 (1988), Sullivan, A. C., et al., Lipids9:121(1973), and Sullivan, A. C., et al., Lipids 9:129 (1973).

However, in order to formulate the compositions containing hydroxycitricacid into dietary supplements and food products, a number of desirableproperties are sought. First, as most such supplements and food productsare administered orally, the composition should have negligible odor andtaste. Second, in order to increase the bioavailability of thehydroxycitric acid, the composition should be soluble in water.

Solubility in water, as well as clarity in solution, are also importantproperties in many food and beverage applications. In addition, it ishighly desirable that the composition be non-hygroscopic, in order tofacilitate storage and formulation into dietary supplements and foodproducts. Another desirable property is the hydroxycitric acid potencyof the composition, where high potency levels are desirable.

SUMMARY OF THE INVENTION

The present invention provides hydroxycitric acid compositions, foodproducts made therefrom and methods for their use in reducing bodyweight.

In one aspect, the invention provides a hydroxycitric acid compositionfor reducing body weight wherein the composition comprises approximately14 to 26% by weight of calcium, and approximately 24 to 40% by weight ofpotassium or approximately 14 to 24% by weight of sodium, or a mixturethereof, calculated as a percentage of the total hydroxycitric acidcontent of said composition.

In another aspect of the invention, a composition for reducing bodyweight is provided which comprises at least approximately 40% by weightof total hydroxycitric acids which further comprise approximately 5 to13% by weight of calcium, and approximately 9 to 20% by weight ofpotassium or approximately 5 to 12% by weight of sodium, or a mixturethereof, calculated as a percentage of the total weight of saidcomposition.

Additional aspects of the invention include dietary supplements and foodproducts for use in reducing body weight which include the presentcompositions, and methods for reducing body weight by administering suchcompositions, dietary supplements and food products to mammals.

DETAILED DESCRIPTION OF THE INVENTION

Hydroxycitric acid has been known for years to be useful for inhibitingfatty acid synthesis. Citrate is formed in the mitochondria by thecitrate synthase reaction.

It is then metabolized via the citric acid cycle. Under certainmetabolic conditions, some citrate is diverted to the cell cytosol whereit is used for fatty acid synthesis, that is, for energy storage. Theinhibition of fatty acid synthesis in biological systems by the use ofhydroxycitric acid is believed to arise from the inhibition of thecitrate cleavage enzyme citrate-lyase by such compounds. The cleavage ofcitrate is catalyzed by citrate-lyase and citrate is the major source ofthe acetyl group of acetyl coenzyme A which is utilized in theconversion of carbohydrates and various amino acids to fats bynon-ruminant mammals.

Typically, hydroxycitric acid is utilized in the form of itspharmaceutically acceptable, non-toxic basic salts. Such salts include,for example, the alkali metals, e.g. sodium and potassium, the alkalineearth metals, e.g. calcium and magnesium, and complex salts, such asammonium or substituted ammonium salts.

In preparing various salts of hydroxycitric acid, it has been found thatthe pure potassium salt was highly soluble in water, but possessed highhygroscopicity, an undesirable property. It was also determined that thepure calcium salt was moderately soluble in water, and possessed minimalhygroscopicity, a desirable property.

Surprisingly, it has been determined that a mixture of calcium salt withpotassium or sodium salts produces a composition which is highly soluble(up to 25% weight to volume in water), but with minimal hygroscopicity.

Furthermore, the composition according to the present invention displaysminimal palatability concerns, as the taste of free hydroxycitric acidis almost entirely eliminated, as well as exceptional productapplication properties, including negligible odor, taste and color.While normally brown, the composition was found to be clear in solution.

In addition, the composition was found to be largely free of the lactoneform of hydroxycitric acid, and that in solution it did not equilibratebetween the free and lactone forms. Further desirable propertiesincluded a balanced pH, and a low (<1%) sodium content. Although sodiumis an acceptable replacement for potassium in the present compositions,its inclusion is considered undesirable for considerations of minimizingdietary intake.

Thus the present compositions demonstrate a surprising, synergisticrelationship between the calcium content and the potassium (or sodium)content. It has been determined that for a composition where the totalhydroxycitric acid content exceeds 40% by weight, a total of salts ofhydroxycitric acid which desirably comprise approximately 5 to 13% byweight of calcium, preferably approximately 7 to 13%, and approximately9 to 20% by weight of potassium, preferably approximately 14 to 18%, orapproximately 5 to 10% by weight of sodium, or mixtures of potassium andsodium.

As stated earlier, although sodium is acceptable, it is considereddesirable to minimize the content of sodium, desirably to less than 1%by weight.

It is further considered desirable to provide a composition in which thetotal hydroxycitric acid content is at least approximately 40% byweight, preferably at least approximately 50%, and desirablyapproximately 55-65%. Thus, in another aspect of the invention, acomposition for reducing body weight is provided which comprises atleast approximately 50% by weight of total hydroxycitric acids whichfurther comprise approximately 5 to 13% by weight of calcium, andapproximately 9 to 20% by weight of potassium or approximately 7 to 12%by weight of sodium, or a mixture thereof, calculated as a percentage ofthe total weight of said composition. Of the total amount, it is alsoconsidered desirable that the amount of hydroxycitric acid in the formof the lactone not exceed approximately 2% by weight.

It is considered desirable to enrich the purity of free hydroxycitricacid from the Garcinia rind and prepare a calcium salt of thehydroxycitric acid. Generally, commercially available Garcinia rindcomprises 25 to 30% moisture and 2 to 5% of sodium chloride. Garciniarind contains 10 to 12% of free hydroxycitric acid, 12 to 15% of thelactone form of hydroxycitric acid and 2 to 3% citric acid on dry weightof the rind.

A further aspect of the preparation of the salt of hydroxycitric acid isto mask the sour taste of hydroxycitric acid, minimize the percentage ofhydroxycitric acid lactone and prepare a sodium free salt ofhydroxycitric acid. The process generally comprises washing the Garciniarind, extracting hydroxycitric acid from the Garcinia rind, preparing aninsoluble calcium salt of the hydroxycitric acid, dissociating theinsoluble calcium salt and thereafter preparing calcium and potassiumsalts of hydroxycitric acid. The washing of the Garcinia rind isoptional, as the sodium chloride can be reduced at other stages in theprocessing.

The salt free water extract can be obtained from salted Garcinia rind bywashing the Garcinia rind followed by hot extraction. The dilute waterextract is filtered through a filtrate after adding clay to the extractand settled. The filtered dilute extract is then concentrated to 45%total solids under reduced pressure at elevated temperature.

This concentrate contains 10 to 12% of free hydroxycitric acid byweight, 11 to 13% of hydroxycitric acid lactone by weight and 2 to 3% ofcitric acid by weight.

The content of free hydroxycitric acid, hydroxycitric acid lactone,citric acid and non acid solutes can be determined by known techniques.

The process of enriching free hydroxycitric acid from the rind isaccomplished by preparing a water extract of the rind, converting theextract into a insoluble calcium citrate and removing non acidicimpurities in the extract, such as pectin, sugar and color which willsolubilize, by washing the calcium hydroxycitrate. Thereafter, thecalcium hydroxycitrate is dissociated with dilute phosphoric acid toform hydroxycitric acid and calcium phosphate. The calcium phosphate isthen filtered out and the enriched hydroxycitric acid solution isconverted to highly soluble calcium salt by first adjusting the pH ofthe hydroxycitric acid solution to 3.5 to 5 with calcium hydroxidesuspension and second by the addition of potassium hydroxide solution toadjust the final pH to 8.0 to 9.0. This calcium salt solution is thenfiltered and concentrated under reduced pressure to approximate 50%total solids. The concentrate is then treated with 75% alcohol/acetoneto crystallize white crystalline highly soluble calcium salt.

There are numerous protocols available for preparing hydroxycitric acidextracts from Garcinia fruits. The rind of the Garcinia fruit which iscommercially available typically consists of approximately 20%hydroxycitric acid, approximately 25% moisture and approximately 2.5%sodium chloride. It is considered desirable to eliminate as much sodiumchloride from the rind as possible and since sodium chloride is freelysoluble in water, this is easily accomplished. For example, one kilogramof raw Garcinia rind material is washed with approximately 2 liters ofwater in a stainless steel vessel. Thereafter, salt free Garcinia rindis extracted with 55 to 60″C water on a continuing basis withapproximately 15 liters of water. The spent rind is then tested forhydroxycitric acid content and typically discarded. At this stage,recovery of total hydroxycitric acid is on the order of 90+2%.

Next, approximately 2.5 kilograms of Fuller's Earth (a kaolin containingan aluminum magnesium silicate) is added to the solution obtainedpreviously. The mixture is stirred for one hour with continuousagitation at approximately 100 revolutions per minute then allowed tosettle for two hours. Thereafter, the material is filtered through a bedof a filter aid in a centrifuge. The filtrate is concentrated to 800grams of approximately 45% total solids containing approximately 22%total hydroxycitric acid content. The yield at this step isapproximately 97% of the extracted hydroxycitric acid.

Next, the concentrated extract is filtered in a centrifuge to removesolids. To the filtered extract is added calcium hydroxide (100 grams in500 ml of water). The mixture is stirred for approximately four hoursmaintaining the pH of the solution at approximately 8.5. Thereafter, themixture is filtered through the centrifuge and the supernatant isdiscarded. The moist pellet is washed continuously with 5 liters ofwater until the water is colorless and no solids are extracted from thefiltrate. The yield of hydroxycitric acid at this phase is approximately96.5%. In the next step, the wet pellet of calcium hydroxycitrateobtained previously is treated with 500 ml of 2N phosphoric acidsolution to convert the calcium hydroxycitrate to hydroxycitric acid andcalcium phosphate. Calcium phosphate precipitate is removed bycentrifugation and washed with 2 liters of water. The filtrate containsapproximately 165 grams of hydroxycitric acid with total solids ofapproximately 6.8% and the hydroxycitric acid yield is approximately91.6%.

Finally, the hydroxycitric acid solution obtained previously is treatedwith calcium hydroxide (61.7 grams in 600 ml of water to adjust to pH4.5). This solution is treated with neutral charcoal (60 grams at 75° C.for two hours under agitation, cooled and filtered). To the filtrate isadded potassium hydroxide (52 grams in 50 ml of water), which adjuststhe pH to between 8.0 and 8.5. This salt solution is concentrated to 555grams under reduced pressure to provide 50% total solids. Theconcentrate is treated with 75% acetone to obtain pure crystallinehighly soluble calcium salt of hydroxycitric acid.

The amount of (−) hydroxycitric acid can be estimated by high pressureliquid chromatography (HPLC), generally as follows.

Estimation of (−) HCA by HPLC:

-   HPLC System: SHIMADZU or equivalent-   LC 1OAT Pump or equivalent-   SPD 10 Detector or equivalent-   CR 10A Software or equivalent-   Column: ALLTIMA C,2(5,u) (4.6×250 mm)-   Wave Length: 210 nm-   Flow rate: 1 mL/min-   Volume of Injection: 20 kL-   Temperature: 25+2 C.

Mobile Phase: 0.05M sodium sulphate solution in water (pH adjusted toapproximately 2.3 with conc. H2SO4).

Standards: 1) Ethylenediamine Salt of (−) HCA.

2) (−) HCA Lactone.

Standards Preparation: Weigh accurately about 50 mg of each standardinto two different 25 mL volumetric flasks. Dissolve in water and makeup to volume with water. Filter through 0.22,u membrane filter andinject the standard solutions separately.

Sample preparation: Weigh accurately about 50 mg of sample in a 25 mLvolumetric flask. Dissolve it in water and make up the volume withwater.

Filter through 0.22,u membrane filter and inject the solution.

Retention Times: for free (−) HCA −5 min.

(−) HCA Lactone −4.1 min.

Calculations: % of Free (−) HCA=Sample Area×Standard Conc.×Purity ofStandard

Standard Area×Sample Conc.

-   % of (−) HCA Lactone=Sample Lactone Area×Lactone Standard    Conc.×Purity of Lactone-   Lactone Standard Area×Sample Conc.

REAGENTS

-   Unless otherwise stated all chemicals used are reagent grade.-   All glass washed with double distilled water.-   Dilute ammonia solution, 25% w/v.-   Ammonium chloride.-   EDTA-   Mordant Black T mixture-   Sodium sulphate, analytical grade, or equivalent-   Sulphuric acid, analytical grade or equivalent-   WATER SOLUBLE EXTRACTIVES: As per USP XX.-   As per USP (1% Solution)-   MOISTURE CONTENT As per USP (K.F. Titrimeter)-   CALCIUM: Weigh accurately about 10 mg of sample into a100 mL conical    flask, dissolve it in 50 mL of water. Add 2 mL of ammonia—ammonium    chloride (pH 9.2) buffer. Then titrate with 0.01M EDTA solution.-   Using Mordant Black-T Mixture as indicator. End point is blue.-   % of Calcium=Titre value×Molarity of EDTA×0.4×100-   0.01×Weight of the sample in mg.    Estimation of Sodium and Potassium by Flame Photometer:

Place 100 mg of sample in a Silica crucible, and reduce to ash in amuffle furnace at 400″C. Transfer ash into a 50 mL volumetric flask, add1 drop conc. HCl and water to dissolve and make up to volume with water.

Calibrate the flame photometer with 100, 50 and 10 pom standard sodiumand potassium solutions. Now place the sample solution in the flamephotometer. Note the ppm reading corresponding to Sodium and Potassium.

% of corresponding Ion=ppm reading corresponding Ion×50×100 1000×Weightof sample in mg.

By inhibiting the synthesis of fatty acids, hydroxycitric acid is usefulfor the reduction of body weight in mammals. These useful compositionscan be provided in the form of conventional pharmaceutical preparationsor dietary supplements, for example, they can be mixed with conventionalorganic or inorganic inert pharmaceutical carriers or dietarysupplements suitable for oral or parenteral administration, such as, forexample, water, gelatin, lactose, starch, magnesium stearate, talc,vegetable oil, gums or the like. They can be administered inconventional forms, e.g., solid forms, for example powders, tablets,capsules, suppositories or the like; or in liquid forms, for example,suspensions or emulsions. In addition, such compositions can beformulated as a part of a processed food product for example in a formof a bar, baked good, beverage and the like.

Moreover, the pharmaceutical compositions and dietary supplements can besubject to conventional pharmaceutical or dietary supplementsexpedients, such as sterilization, and can contain conventionalpharmaceutical or dietary supplements excipients, such as preservatives,stabilizing agents, emulsifying agents, salts for the adjustment ofosmotic pressure or buffers, and the like. The compositions can alsocontain other therapeutically active materials.

A suitable dosage unit will typically contain from about 15 to about3000 mg of hydroxycitric acid, administered up to three times per day.Suitable parenteral dosage regimens in mammals can comprise from about 1mg per kilogram of body weight to about 50 mg per kilogram of bodyweight per day. However, for any particular subject, the specific dosageregimen should be adjusted according to individual need and theprofessional judgment of the person administering or supervising theadministration of the aforesaid compounds.

Additional aspects of the invention include food products and the likefor use in reducing body weight which include the present compositions,and methods for reducing body weight by administering such compositionsand dietary supplements and food products. When provided for oraladministration as a processed food product, such as a beverage or asnack bar, the hydroxycitric acid content will desirably compriseapproximately 0.001 to 25%, preferably 0.05 to 5% by weight of the totalweight of the food product.

Preparation of processed food products to include hydroxycitric acidcompositions of the present invention involves, for example, diluting aconcentrate of the composition containing at least approximately 40%hydroxycitric acid in water, adding supplements, blending, heatingand/or periodic agitation.

For both snack bars and beverages, it is desirable to pre-pasteurize theconcentrate in a highly diluted ratio with purified water. For example,approximately 1 mL of the concentrate can be added to 12 fluid ounces ofwater. These figures will however vary depending upon the types ofproducts desired, ranging from 1 to 25% for a beverage and 1 to 40% fora snack bar. After the blending step, the temperature of the vesselwhich the preprocessing step takes place is increased, frequently usingsteam as in the case of beverage manufacture or low heat as in the caseof snack bars and baked goods. Before heat is applied, materials such asnutrients, antioxidants, vitamins and minerals can be added. In theproduction of the beverage, after the supplementation of the desiredadditives and achievement of homogeneosity, the liquid is pumped by astainless steel pipeline into a bottling facility. High temperaturesteam is applied from the outside to the pipes which in turn maintainsthe temperature of the liquid during its transit. The pipes are placedso as to facilitate the bottling of the liquid beverage in an efficientmanner.

In the preparation of, for example, snack bars, the preprocessingfollows approximately the same protocol as for beverages. Theenvironment for the development of this product is typically anindustrial kitchen with the use of large cooking pots. The dilutedhydroxycitric acid composition is blended with water, covered andheated, bringing it to a boil for a certain period of time. This boilingalso provides agitation to insure thorough mixing. Thereafter, snackbars, baked goods or other processed food products are produced inaccordance with the techniques well known in the art.

All patents and patent applications cited in this specification arehereby incorporated by reference as if they had been specifically andindividually indicated to be incorporated by reference.

Although the foregoing invention has been described in some detail byway of illustration and example for purposes of clarity andunderstanding, it will be apparent to those of ordinary skill in the artin light of the disclosure that certain changes and modifications may bemade thereto without departing from the spirit or scope of the appendedclaims.

1. A process of producing potassium calcium salt of hydroxycitric acidfrom the rind of Garcinia fruit comprising: (a) preparing a waterextract of the Garcinia rind; (b) precipitating one or morehydroxycitric acid salts out of the water; (c) adding an acid; (d)adding calcium hydroxide to adjust to between: a lower limit ofapproximately pH 3.5; and an upper limit of approximately pH 5; to formcalcium hydroxycitric acid; and (e) adding potassium hydroxide to adjustto between: a lower limit of approximately pH 8; and an upper limit ofapproximately pH 9; to form potassium calcium hydroxycitric acid.
 2. Theprocess of claim 1, where in step (a) further comprises decolorizing thewater extract with a third reagent.
 3. The process of claim 2, whereinthe third reagent is selected from the group consisting of Fuller'sEarth, kaolin and aluminum magnesium silicate.
 4. The process of claim1, wherein the acid is phosphoric acid; wherein the phosphoric acid isadded to re-dissolve the precipitated hydroxycitric acid salts forminginsoluble phosphate-salts.